# Exam 2 Flashcards Preview

## Astronomy > Exam 2 > Flashcards

Flashcards in Exam 2 Deck (165)
1
Q

Light waves and photons carry ________, and the strength of ________ is often given as a power.

A

Energy; light

2
Q

Why are some people color blind?

A

Color is a perception.

3
Q

List the three primary light colors.

A

Red, blue, green

Note: The 3 primary art colors are cyan, magenta, and yellow.

4
Q

Color that contains every other color.

A

White

5
Q

Color representing absence of light.

A

Black

6
Q

Light/Matter Interactions: light leaves matter.

A

Emission

7
Q

Light/Matter Interactions: light enters matter.

A

Absorption

8
Q

Light/Matter Interactions: light travels through matter.

A

Transmission

9
Q

Light/Matter Interactions: light bounces off of matter.

A

Reflection

10
Q

Light/Matter Interactions: random motions as light bounces off matter; during reflection/transmission.

A

Scattering

11
Q

A mirror is an example of ________ reflection.

A

Secular

12
Q

The color we see as an object’s color is ________, and all other colors are ________.

A

Reflected; absorbed

13
Q

What color(s) does an orange shirt reflect? What color(s) does it absorb?

A

Orange; all other colors

14
Q

Properties of Light: The distance from one peak to the next (or one trough to the next) in a light pattern.

A

Wavelength

15
Q

In order to start, wavelengths require a:

A

Disturbance

16
Q

Property of medium; propagate waves.

A

Wave speed

17
Q

How often a light pattern will repeat.

A

Frequency

18
Q

Require a physical medium to propagate through. (Hint: no one in space can hear you.)

A

Mechanical waves

19
Q

Self-sustaining waves propagating through the electromagnetic field.

A

Electromagnetic waves

20
Q

When a wavelength becomes longer, the frequency is ________.

A

Lower

21
Q

Light is carried by ________.

A

Photons

22
Q

List the electromagnetic spectrum from longest to shortest wavelength.

A

Radio, microwave, infrared, visible, ultraviolet, x-ray, and gamma ray.

23
Q

Higher frequency waves have ________ energy.

A

Higher

24
Q

Positively charged particle in the nucleus.

A

Proton

25
Q

Neutral charged particle in nucleus.

A

Neutron

26
Q

Negatively charged particle surrounding nucleus.

A

Electron

27
Q

Atoms are held together by ________ force.

A

Electromagnetic

28
Q

Classifying atoms: depends on protons.

A

Element

29
Q

Classifying atoms: depends on total number of nucleons.

A

Isotopes

30
Q

Classifying atoms: excess or depletion of electrons compared to ordinary state.

A

Ion

31
Q

Number of protons

A

Atomic number

32
Q

Number of protons and neutrons

A

Atomic mass number

33
Q

States of matter: defined shape, defined volume.

A

Solid

34
Q

States of matter: undefined shape, defined volume.

A

Liquid

35
Q

States of matter: undefined shape, undefined volume, compressible.

A

Gas

36
Q

States of matter: ionized gas, most common state of matter in the universe. (Hint: example: stars.)

A

Plasma

37
Q

A spectrum of all colors. Can be produced by reflecting or emitting light.

A

Continuous spectrum

38
Q

Colored lines produced by quantized energy released from storage in an atom or molecule. Used to identify elements and compounds.

A

Emission lines

39
Q

Lines of absorption in a continuous spectrum that result from the light going through a semi-opaque object.

A

Absorption lines

40
Q

Each element has a different ________.

A

Spectrum

41
Q

Emission and absorption lines are produced in molecules by ________ and ________.

A

Rotation; vibration

42
Q

Continuous spectrum of light emitted by an object as a result of the temperature of the object.

A

43
Q

Stefan-Boltzmann Law

A

Hotter objects emit more light.

44
Q

Wien’s Law

A

Hotter objects change colors.

45
Q

Change in frequency of a wave caused by the relative motion of the wave source and absorber with respect to each other.

A

Doppler shift

46
Q

When the wavelength of the light is longer, the light is:

A

Redshifted

47
Q

When the wavelength of light is shorter, the light is:

A

Blueshifted

48
Q

The Doppler shift can tell us how fast an object is:

A

Rotating

49
Q

Acts as a shutter that controls the amount of light going into the optical system.

A

Pupil

50
Q

Focuses the light entering the optical system, uses refraction to direct light.

A

Lens

51
Q

Detects photons entering the optical system.

A

Retina

52
Q

Transport photon information

A

Optical nerve

53
Q

The process by which light can be bent or changed direction.

A

Refraction

54
Q

A measure of how well a medium can bend.

A

Index of refraction

55
Q

The point at which light rays focus and converge at a single point to form an angle.

A

Focal point

56
Q

Not all sources produce parallel rays. The rays focus on this.

A

Focal plane

57
Q

How are images created?

A

From the photons emitted or reflected from the source.

58
Q

The length of time the shutter is open.

A

Exposure time

59
Q

The amount of energy per unit time that is measured or produced.

A

Power

60
Q

A detector is broken up into these multiple pieces.

A

Pixels

61
Q

How much light a telescope can collect at one time.

A

Light-collecting area

62
Q

The smallest angle two dots can be separated/distinguished from each other.

A

Angular separation

63
Q

Actual angular separation depends on ________ and ________ _______.

A

Atmosphere

64
Q

Process where light waves interact with each other.

A

Interference

65
Q

Refracts light to a focal point. Limited by how much a material can refract/bend light.

A

Refracting telescope

66
Q

Reflects light off of multiple mirrors to one focal point. More compact and easier to maneuver.

A

Reflecting telescopes

67
Q

Reflecting telescope: two mirrors, focus at back.

A

Cassegrain

68
Q

Reflecting telescope: two mirrors, focus at side.

A

Newtonian

69
Q

Reflecting telescope: three mirrors, focus at side.

A

Nasmyth/Coude

70
Q

Why do large mirrors need a lot of support?

A

They will break under their own weight.

71
Q

What is a technique to lessen the weight of a telescope?

A

Segmented mirrors

72
Q

How big (m) will the next generation of optical telescopes be?

A

30 meters

73
Q

How are images created?

A

From a single wavelength or multiple wavelengths of light.

74
Q

What limits the wavelengths of light received by a telescope?

A

Filters

75
Q

How do we create images for invisible wavelengths? Explain this process.

A

False-color imaging; invisible wavelengths are translated and matched up with visible wavelengths of light.

76
Q

The technique of analyzing light by looking at the intensity of light for each wavelength of color.

A

Spectroscopy

77
Q

What does spectroscopy do?

A

Separate the various wavelengths, or colors, of light.

78
Q

The amount of information that can be obtained from a spectrography depends on the:

A

Spectral resolution

79
Q

When we decrease intensity for better spectral resolution, we must increase ________ to compensate.

A

Exposure

80
Q

A plot of brightness versus time

A

Light curve

81
Q

A dimming of the night sky due to artificial light (which lessens the sensibly of optical telescopes).

A

Light pollution

82
Q

Does light follow a straight path through our atmosphere? Why?

A

No; it scatters off of the molecules in our atmosphere.

83
Q

What causes the twinkling we see when we are viewing stars?

A

Atmosphere

84
Q

Where could we place a telescope where we could prevent the most interference?

A

On top of a mountain, volcano, space.

85
Q

Do most forms of light or electromagnetic waves penetrate the Earth’s atmosphere?

A

No; most do not.

86
Q

What forms of light can make it to the surface of the Earth?

A

Visible, radio, near IR, and near UV.

87
Q

Telescopes: huge dishes, too large to put in space, penetrate atmosphere easily, have radio wave pollution due to communication.

A

88
Q

Telescopes: designed similar to optical telescope, must be placed high enough in atmosphere and space, pollution easily blocked by non-conducting shield around it.

A

Infrared telescopes

89
Q

Telescopes: designed like IR and visible telescopes, must be placed in space because light is absorbed by the atmosphere, pollution not a concerned, excess waves blocked by shielding.

A

Ultraviolet telescopes

90
Q

Telescopes: too energetic to be reflected or refracted like most forms of light, can only change direction a small amount when they interact with a surface, use grazing incidence mirrors to change direction of light photons a little with each reflection.

A

X-ray telescopes

91
Q

Telescopes: so energetic they cannot be reflected, must be detected without any focusing, limiting its angular resolution.

A

Gamma ray telescopes

92
Q

Large pools of water/ice under ground

A

Neutrino Detector

93
Q

Very small, neutral subatomic particles produced by the sun

A

Neutrino

94
Q

Both ground and space based little known about them

A

Cosmic Ray Detector

95
Q

Very energetic subatomic particles

A

Cosmic rays

96
Q

Large interferometers used to detect gravitational waves predicted by Einstein

A

Gravitational Waves Detectors

97
Q

Technique of combining information from multiple telescopes to create a single image or spectrum

A

Interferometry

98
Q

Which telescope would be better used and why: an extra telescope located in Antarctica, used to examine the sun’s Corona, or an x-ray telescope placed on a satellite in orbit around the earth, used to examine their sun’s Corona?

A

The x-ray on a satellite, because there are atmospheric interferences and though being in space would be more expensive, it would make more sense.

99
Q

Which telescope would be better used and why: and ultraviolet telescope located at the summit of Mauna Kea, Hawaii, used to study galaxies, or an optical telescope located at the summit of Mauna Kea, Hawaii, used to study galaxies?

A

The optical telescope, because the ultraviolet telescope will not be of any use because it must be in space.

100
Q

What telescope would be better used and why: an infrared telescope located at the summit of Mauna Kea, Hawaii, used to observe comets, or an infrared telescope placed on a satellite in orbit around Earth, used to observe comets?

A

The telescope located at the summit of Mauna Kea, because it can easily block pollution, and it is cheaper to place it on earth then in space.

101
Q

What holds the solar system together?

A

The sun’s gravitational force

102
Q

True or false: The sun’s mass is greater than the combined mass of the rest of the solar system.

A

True

103
Q

The sun is normal except for this trait.

A

High metallicity

104
Q

The sun is 98% ________ and ________.

A

Hydrogen; helium

105
Q

Dark spots on the surface of the sun; they are cooler than the rest of the sun.

A

Sun spots

106
Q

Why is the sun yellow in color?

A

107
Q

By what process does the sun create its energy by converting mass to energy?

A

Nuclear fusion

108
Q

Bombard the objects in the solar system (not comets, asteroids, etc.)

A

Solar winds

109
Q

Bursts of hot plasma from the surface of the sun

A

Solar flare

110
Q

Type of planets that is closer to the sun, including Mercury, Venus, Earth, and Mars.

A

Terrestrial planets

111
Q

Type of planet that is farther from the sun, including Jupiter, Saturn, Uranus, and Neptune.

A

Jovian planets

112
Q
```No atmosphere
Heavily cratered
Extreme temperature difference between night and day
Smallest planet
Closest to sun```
A

Mercury

113
Q
```Hottest planet
Has atmosphere
Closest physical characteristics to Earth
Spins backwards
Second closest to sun```
A

Venus

114
Q
```Densest planet
Oxygen/nitrogen atmosphere
Moon closest size to host planet
Innermost planet with a moon
Only habitable planet in solar system```
A

Earth

115
Q

Very little atmosphere
No magnetic field
Shows history of geological activity
Two moons, probably captured asteroids

A

Mars

116
Q

Not a planet
Most likely a produce of an unformed planet
Largest asteroid, Ceres, is a dwarf planet

A

Asteroid Belt

117
Q

Largest planet
Smallest axis tilt
Red spot-giant storm size of Earth
4 large moons (Galilean moons)

A

Jupiter

118
Q

Which one of Jupiter’s moons is most likely to be a candidate for a potential colony? Also note: largest moon in solar system.

A

Ganymede

119
Q

Less dense than water
Would float in an ocean
Has one moon Titan

A

Saturn

120
Q

Coldest planet
Longest year
Only one visit from satellite (Voyager 2)

A

Neptune

121
Q

Rotates nearly on its side
No solid surface
Closest planet with only one satellite visit (Voyager 2)

A

Uranus

122
Q

Lost planet status, has not cleared its orbit, in the Kuiper belt, it’s largest moon, Charon, is locked and synchronous rotation with its host planet.

A

Pluto

123
Q

Similar to the astroid belt, except that it’s objects are icy balls. Has a dwarf planet called Eris.

A

Kuiper belt

124
Q

Leftover, cold material, distributed spherically around the sun. Likely source of comets

A

Oort Cloud

125
Q

Dirty balls of ice. Tail created by radiation energy from the sun, points away from the sun.

A

Comets

126
Q

Other than telescopes, what are other sources of information about planets?

A

Robotic missions

127
Q

What are the four types of robotic missions?

A

Flybys, orbiters, landers, and sample return missions

128
Q

Robotic missions: spacecraft passes by the object only once and then continues. Only type that can visit multiple planets. Cheapest. Only type of mission used for outer planets. Uses gravitational slingshot.

A

Flybys

129
Q

Robotic missions: goes to planet and orbits it like a moon. Can gather information over a long period of time on one source. Provides most accurate measurement of the mass of orbited planet. More expensive than flybys, but information per cost is better.

A

Orbiters

130
Q

Robotic missions: land on surface and explores surface of an object. Allows direct analysis of material. Costlier and more challenging. Due to harsh conditions, the robot has a shorter lifespan.

A

Landers

131
Q

Robotic missions: what are the steps to getting a lander on the surface of an object?

A
1. Friction slows spacecraft.
2. Parachute slows spacecraft.
3. Rockets slow spacecraft to halt; “Sky crane” lowers rover to surface.
4. Tether releases, rocket heads off to crash a safe distance away.
132
Q

Robotic missions: a sample is returned to Earth for analysis. Most difficult and most costly. Allows for more depth analysis. Other missions limited by payload size.

A

Sample return mission

133
Q

What are some common characteristics between all the planets?

A

They all travel in the same direction around the sun, have nearly circular orbits, and are about in the same plane of space.

134
Q

Explains major features of solar system. Being tested and adjusted as new planetary systems are discovered.

A

Nebular Theory

135
Q

NASA panel; types of robotic missions: what robotic mission would best suit studying the atmosphere of the planet Neptune?

A

Orbiter

136
Q

NASA panel; types of robotic missions: what robotic mission would best suit studying the composition of the Cerus dwarf planet in the asteroid belt?

A

Sample Return

137
Q

NASA panel; types of robotic missions: what robotic mission would best suit studying several comets/asteroids in the Oort Cloud?

A

Flyby

138
Q

NASA panel; types of robotic missions: what robotic mission would best suit studying the surface geology of Jupiter’s moon, Ganymede?

A

Landers

139
Q

Bigger stars burner their fuel ________ than smaller stars.

A

Faster

140
Q

Resulting from the conversion of potential energy into kinetic energy (note: higher temperature at center)

A

Heating

141
Q

Nebula spins as energy is converted

A

Spinning

142
Q

Caused by spinning, centripetal force holds material outwards

A

Flattening

143
Q

Gathering of material increasing the size of an object

A

Accretion

144
Q

How did the Terrestrial planets form?

A

Accretion (materials gathering), metal gathering until planetesimals form, becomes hard to grow. Only largest continue to grow. (Evidence: meteorites have same composition needed for solar nebula theory.)

145
Q

How were the Jovian planets formed?

A

Similar to terrestrial planets, except that they use hydrogen compounds.

146
Q

How does the sun “clear the nebula”?

A

The early sun rotated rapidly and had a stronger solar wind. Solar wind would push materials toward the edge of the solar system.

147
Q

Pieces that were never accreted into larger objects, many hit planets in heavy bombardment period, many impact craters provide evidence.

A

Asteroids and comets

148
Q

What are some exceptions to the rules?

A

The Earth’s moon is very large compared to its host planet, Mars has two moons, Venus’s rotation backwards, Uranus tilts on its side, Mercury has a large core.

149
Q

What are captured moons?

A

Leftover planetesimals

150
Q

Why is Earth’s moon so big?

A

Result of a giant impact: when Earth was molten, a Mars-sized planetesimal collided with the Earth. Resulted with a debris disk around the planet. The debris accreted into a moon.

151
Q

What is a likely reason Uranus spins on its side?

A

Giant collision

152
Q

Why does Venus spin backwards?

A

Giant collision or probably atmosphere

153
Q

Mercury’s core?

A

Giant collision

154
Q

How did the asteroid belt form?

A

It was an unformed planet, possibly caused by Jupiter’s gravity.

155
Q

The age of rocks can be determined from when they ________.

A

Solidify

156
Q

Uses radioactive elements and their decay rates to figure out life period of element

A

157
Q

Amount of time required for half the element to decay

A

Half-life

158
Q

Earth rocks have been dated to ___ billion years ago.

A

4

159
Q

Moons rocks have been dated to ___ billion years ago.

A

4.5

160
Q

Meteorites have been dated to ___ billion years ago.

A

4.55

161
Q

Solar system is ___ billion years old.

A

4.5

162
Q

New solar systems, reasonable or surprising: The solar system has four large Jovian planets and it’s in our solar system and six small terrestrial planets in its outer solar system.

A

Surprising due to frost line

163
Q

New solar systems, reasonable or surprising: A solar system with 11 planets, all orbiting in the same plane and direction around the host star. The 17 largest moons in the solar system orbit their planet in nearly the same plane and direction. However, many small moons have highly inclined orbits around their planets.

A

Reasonable

164
Q

New solar systems, reasonable or surprising: A solar system has four Earth-sized terrestrial planets, each with a single moon, identical in size to the Earth’s moon. There are no Jovian planets.

A

Surprising because the moons are the same size as their host and there are no Jovian planets.

165
Q

New solar systems, reasonable or surprising: A solar system has several planets similar and composition to the Jovian planets, but similar in size to the terrestrial planets of our solar system.

A

Surprising and reasonable, depending on the size of the host star. If host star is dwarf, reasonable. If star is same size as Milky Way host, surprising.